; **************************************************************************** ; ; TRFDBOOT.ASM ; ; Turkish Rational's ; (MS-DOS 6.2 Clone) Disk Operation System v1.0 Project ; TR-DOS Executer (MS-DOS Filesystem) Presentation 2000 Floppy Disk Boot Code ; ; Copyright (C) 1998 Erdogan TAN [ Last Modification: 18/04/2000 ] ; ; **************************************************************************** trmagicword equ 01A1h notvalidfmask equ 0018h destination equ 7E00h bootstack equ 7BFAh sizeBPB equ 0019h sizeofdirentry equ 0020h RxDOSBOOT SEGMENT PUBLIC 'CODE' assume cs:RxDOSBOOT, ds:RxDOSBOOT, es:RxDOSBOOT, ss:RxDOSBOOT org 100h ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Write Stub ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; ; ; The stub loads at the normal 100h load address and writes ; ; the boot sector to drive A: ; ;...............................................................; RxDOS_WRITESTUB: cli cld push cs pop ss mov sp, 0FFFEh sti ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; see if drive specified ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - mov si, offset 80h ; PSP command tail mov cl, byte ptr [ si ] or cl, cl jz RxDOS_WRITESTUB_12 ; jump if zero RxDOS_WRITESTUB_06: inc si mov al, byte ptr [ si ] cmp al, ' ' ; is it SPACE ? jnz RxDOS_WRITESTUB_08 dec cl jnz RxDOS_WRITESTUB_06 jmp short RxDOS_WRITESTUB_12 RxDOS_PRINT proc near RxDOS_PRINT_LOOP: lodsb ; Load byte at DS:SI to AL and AL,AL jz RxDOS_PRINT_OK mov AH,0Eh mov BX,07h int 10h ; BIOS Service func ( ah ) = 0Eh ; Write char as TTY ;AL-char BH-page BL-color jmp RxDOS_PRINT_LOOP RxDOS_PRINT_OK: retn RxDOS_PRINT endp RxDOS_WRITESTUB_08: cmp al, '0' ; 0 - 9 jc RxDOS_WRITESTUB_12 cmp al, '9' + 1 ; allow number for drive jc RxDOS_WRITESTUB_09 cmp al, 'A' jc RxDOS_WRITESTUB_12 cmp al, 'Z' + 1 ; A - Z jc RxDOS_WRITESTUB_10 cmp al, 'a' ; a - z jc RxDOS_WRITESTUB_12 cmp al, 'z' + 1 jnc RxDOS_WRITESTUB_12 sub al, 'a'-'A' ; to upper case ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; get drive code ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_10: mov byte ptr RxDOS_DRIVE, al jmp RxDOS_WRITESTUB_20 RxDOS_WRITESTUB_09: add al, 'A'-'0' ; 0 based -> A based jmp RxDOS_WRITESTUB_10 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Write message ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_12: mov si, offset RxDOS_Welcome call RxDOS_PRINT cmp cl,0 ja RxDOS_WRITESTUB_60 RxDOS_WRITESTUB_13: mov si, offset RxDOS_PressKeyWhenReady call RxDOS_PRINT RxDOS_WRITESTUB_14: xor ax, ax int 16h ; wait for keyboard command push ax mov si, offset RxDOS_CRLF call RxDOS_PRINT pop ax cmp al, 'M'-40h ; Enter (OK) key jz RxDOS_WRITESTUB_20 ; write cmp al, 'C'-40h jz RxDOS_WRITESTUB_60 ; no write (exit) cmp al, 27 jz RxDOS_WRITESTUB_60 jmp RxDOS_WRITESTUB_13 ; No write (exit) ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; get drive parameters ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_20: mov ah, 08h mov dl, byte ptr RxDOS_DRIVE ; drive sub dl, 'A' ; make it zero based int 13h ; return disk parameters push cs pop es ; restore es: xor bh, bh mov ax, bx ; drive type dec ax ; make it zero based mov cx, sizeBPB mul cx mov si, offset DriveDefaultData add si, ax mov di, offset bsBytesPerSec rep movsb ; copy correct BPB info xor ax, ax int 1Ah ; get time of day mov word ptr [bsVolumeID], dx mov word ptr [bsVolumeID+2], cx ; set unique volume ID mov ax, 0301h ; write to disk mov bx, offset start ; location of boot code mov ch, 00 ; cylinder = 0 mov cl, 01 ; sector = 1 mov dh, 00 ; head = 0 mov dl, byte ptr RxDOS_DRIVE ; drive sub dl,'A' ; make it zero based int 13h jnc RxDOS_WRITESTUB_36 ; if everything is ok --> RxDOS_WRITESTUB_30: mov si, offset RxDOS_disk_NotReadyOrError call RxDOS_PRINT jmp short RxDOS_WRITESTUB_40 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; success. try again ? ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_36: mov si, offset RxDOS_disk_WrittenSuccesfully call RxDOS_PRINT jmp RxDOS_WRITESTUB_60 RxDOS_WRITESTUB_40: xor ax, ax int 16h ; wait for keyboard command push ax mov si, offset RxDOS_CRLF call RxDOS_PRINT pop ax cmp al, 'y' jz RxDOS_WRITESTUB_13 ; retry cmp al, 'Y' jz RxDOS_WRITESTUB_13 cmp al, 'n' jz RxDOS_WRITESTUB_60 ; exit cmp al, 'N' jz RxDOS_WRITESTUB_60 cmp al, 'C'-40h jz RxDOS_WRITESTUB_60 cmp al, 27 jz RxDOS_WRITESTUB_60 jz RxDOS_WRITESTUB_30 ; repeat the message RxDOS_WRITESTUB_60: mov ax, 4c00h ; terminate int 21h ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; messages ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_Welcome: db 0Dh, 0Ah db 'TR-DOS Floppy Disk Boot Sector Rebuilder v1.0' db 0Dh, 0Ah db '(c) Erdogan TAN 1998' db 0dh,0Ah db 0Dh,0Ah db 'Usage: trfdboot [drive]' RxDOS_CRLF: db 0Dh, 0Ah, 0 RxDOS_PressKeyWhenReady: db 0Dh, 0Ah db 'Press Enter to write boot sector on disk ' RxDOS_Drive: db 'A: ', 0 RxDOS_disk_WrittenSuccesfully: db 0Dh, 0Ah db 'Boot sector updated to TR-DOS X format...' db 0Dh, 0Ah db 0 RxDOS_disk_NotReadyOrError: db 0Dh, 0Ah db 'Disk error or drive not ready. Try again? (Y/N) ' db 0 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Drive Default Data ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - DriveDefaultData: ; 360k drive **needs updating** dw 512 ; BytesPerSector db 1 ; SectorsPerCluster dw 1 ; ResSectors db 2 ; NumCopiesFAT dw 00E0h ; MaxAllocRootDir dw 0960h ; MaxSectors db 0f9h ; MediaDescriptor dw 7 ; SectorsPerFat dw 15 ; SectorsPerTrack dw 2 ; Heads dd 0 ; HiddenSectors dd 0 ; HugeSectors ; 1.2M drive dw 512 ; BytesPerSector db 1 ; SectorsPerCluster dw 1 ; ResSectors db 2 ; NumCopiesFAT dw 00E0h ; MaxAllocRootDir dw 0960h ; MaxSectors db 0f9h ; MediaDescriptor dw 7 ; SectorsPerFat dw 15 ; SectorsPerTrack dw 2 ; Heads dd 0 ; HiddenSectors dd 0 ; HugeSectors ; 720k drive **needs updating** dw 512 ; BytesPerSector db 1 ; SectorsPerCluster dw 1 ; ResSectors db 2 ; NumCopiesFAT dw 00E0h ; MaxAllocRootDir dw 0960h ; MaxSectors db 0f9h ; MediaDescriptor dw 7 ; SectorsPerFat dw 15 ; SectorsPerTrack dw 2 ; Heads dd 0 ; HiddenSectors dd 0 ; HugeSectors ; 1.44M drive dw 512 ; BytesPerSector db 1 ; SectorsPerCluster dw 1 ; ResSectors db 2 ; NumCopiesFAT dw 224 ; MaxAllocRootDir dw 2880 ; MaxSectors db 0f0h ; MediaDescriptor dw 9 ; SectorsPerFat dw 18 ; SectorsPerTrack dw 2 ; Heads dd 0 ; HiddenSectors dd 0 ; HugeSectors db '(c) Erdogan TAN 1998' db 1 dup (?) ; trick for assembler ; to keep 'start' ; at 7C00h org 7C00h ;±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±± ;± ;± PROCEDURE proc_start ;± ;±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±± proc_start proc near start: jmp short loc_2 nop ; BootSector Identification (Data) Block bsOemName db 'TR-DOS X' bsBytesPerSec dw ? bsSecPerClust db ? bsResSectors dw ? bsFATs db ? bsRootDirEnts dw ? bsSectors dw ? bsMedia db ? bsFATsecs dw ? bsSecPerTrack dw ? bsHeads dw ? bsHiddenSecs label dword bsHidden1 dw ? bsHidden2 dw ? bsHugeSectors label dword bsHugeSec1 dw ? bsHugeSec2 dw ? bsDriveNumber db ? bsReserved1 db ? bsbootsignature db 29h bsVolumeID dd ? bsVolumeLabel db 11 dup(?) bsFileSysType db "FAT12 " bsReserved2 dw ? loc_2: xor AX,AX mov DS,AX mov ES,AX mov SS,AX mov SP,bootstack ; 7BFAh mov BP,7C00h ; Bootsector location on memory mov DL,byte ptr bsDriveNumber ; Fixed. 18/04/2000 int 13h ; BIOS Service func ( ah ) = 0 ; Reset disk system jc short loc_ioerr ; To print i/o error message loc_3: ; AX = 0 for AMIBIOS (no error) mov AL,Byte Ptr bsFATs ; BP+10h = Number of FATs mul Word Ptr bsFATsecs ; BP+16h = # of FAT sectors add AX,Word Ptr bsHidden1 ; BP+1Ch = Hidden sectors LSW adc DX,Word Ptr bsHidden2 ; BP+1Eh = Hidden sectors MSW add AX,Word Ptr bsResSectors; BP+0Eh = Reserved sectors adc DX,0 ; ADD with carry push AX ; LSW of root directory location push DX ; MSW of root directory location mov Word Ptr [BP-4],AX ; LSW of Data Area = 7BFCh mov Word Ptr [BP-2],DX ; MSW of Data Area = 7BFEh mov AX,sizeofdirentry ; Size of a directory entry (32) mov SI,Word Ptr bsRootDirEnts ; BP+11h = Root dir entries mul SI ; DX_AX = AX * data mov BX,Word Ptr bsBytesPerSec ; BP+0Bh = Bytes per sector add AX,BX ; Round up dec AX div BX ; AX=AX_DX/data DX=AX_DX%data add Word Ptr [BP-4],AX ; Location of the first data cluster adc Word Ptr [BP-2],0 ; pop DX ; DX_AX = Location of root directory pop AX loc_4: mov BX,destination ; Destination offset = 7E00h mov DI,BX mov CX,1 ; Sector count for transfer call proc_read loc_5: jc short loc_failed ; Transaction failed message loc_6: cmp Byte Ptr [DI],00h ; Is it null entry? je short loc_nofile ; Jump if zero ( = ) mov CX,0Bh ; Size of file/directory name push SI ; SI = number of the entries push DI mov SI,offset stdfilename ; Offset of the std file name repe cmpsb ; Repeat if ZF = 1, CX > 0 ; Cmp byte at DS:SI to ES:DI pop DI pop SI je short loc_found ; If the file name found dec SI jz short loc_nofile ; Jump if no next entry add DI,20h ; To next directory entry cmp DI,BX ; Any more on current sector? jb short loc_6 ; Jump if it is no last jmp short loc_4 ; Jump for next sector loc_nofile: mov Byte Ptr notfoundmsg,20h mov SI,offset stdfilename jmp short loc_9 loc_boss: mov DI,trmagicword jmp short loc_9 loc_ioerr: mov SI, offset IOerrormsg jmp short loc_9 loc_failed: mov SI,offset failmessage loc_9: lodsb ; Load byte at DS:SI to AL and AL,AL je short loc_reboot ; If AL = 00h then stop mov AH,0Eh mov BX,07h int 10h ; BIOS Service func ( ah ) = 0Eh ; Write char as TTY ;AL-char BH-page BL-color jmp short loc_9 loc_reboot: mov SI,offset rebootmsg cmp DI,trmagicword ; Replace/Reboot msg control jne loc_boss ; Print Replace/Reboot message xor AX,AX int 16h ; BIOS Service func ( ah ) = 0 ; Read next kbd char ;AH-scan code AL-char code int 19h ; Reboot infinite_loop: jmp short infinite_loop ; Never come here ! loc_found: mov AL,Byte Ptr [DI+0Bh] ; Move attributes byte to BL and AL,notvalidfmask ; Is it a file, really? ja short loc_nofile ; Jump if above ( > ) mov AX,Word Ptr [DI+1Ah] ; First cluster of the file cmp AX,02h ; Start cluster jb short loc_failed ; If It is invalid ( < 2 ) mov AX,DI mov Word Ptr bsReserved2,AX ; Save the first cluster ; for using by presentator dec AX ; First cluster is cluster 2 dec AX mov CL,Byte Ptr bsSecPerClust mul CX ; DX_AX = AX * data add AX,Word Ptr [BP-4] adc DX,Word Ptr [BP-2] ; ADD with carry mov BX,destination push BX call proc_read ; CX = sectors per cluster pop BX jb short loc_ioerr ; If CF = 1 then I/O err msg jmp BX ; Jump to 7E00h dw 0000h,0070h ; seg : off proc_start endp proc_read proc near loop_loc_14: push CX push AX ; PHYSICAL ADRESS CALCULATION push DX ; DX_AX = Linear address div Word Ptr bsSecPerTrack ; BP+18h = Sectors per track mov CX,DX ; Sector (zero based) inc CL ; To make it 1 based xor DX,DX div Word Ptr bsHeads ; Convert track to head/cylinder ; AX = cyl, DX = head, CX = sector mov DH,DL mov DL,Byte Ptr bsDriveNumber mov CH,AL ror AH,1 ; Rotate right ror AH,1 or CL,AH mov AX,0201h int 13h ; BIOS Service func ( ah ) = 2 ; Read disk sectors ;AL-sec num CH-track CL-sec ; DH-head DL-drive ES:BX-buffer ;CF-flag AH-stat AL-sec read pop DX pop AX pop CX jc short loc_16 add AX,01h adc DX,0h jc short loc_16 loc_15: add BX,Word Ptr bsBytesPerSec loop loop_loc_14 ; Loop if CX > 0 loc_16: retn proc_read endp dw 0 IOerrormsg db 'Disk I/O error...',0 failmessage db 'Transaction failed...',0 rebootmsg db 0Dh, 0Ah db 'Replace the disk, and press any key to reboot...' db 0Dh, 0Ah,0 db 0 stdfilename db 'PRESENTATOR' notfoundmsg db 0, 'not found...', 0 version db 'TR-DOS Boot v1.0', 0 db 0 db '¸ Erdo§an Tan [ 1998-2000 ]' db 0 bossmagic db 01h db 0A1h db 1 dup(0) org start+200h-2 bootsignature db 55h, 0AAh RxDOSBOOT ends end RxDOS_WRITESTUB